someone (m) who protected him/someone whom he protected

Are there any word choice/sentence/syntactic cues that can be used to distinguish these two if both the protector and the protected use the same pronoun? For example is "מישהו שהגן עליו" usually the former and "מישהו שעליו הוא הגן" the latter?

Then how does one say "someone whom he protected"?
Edit: OK, I think I resolved this question. מישהו שהגן עליו may refer to either (most likely understood as "someone who protected him" because of the verb in the front of the clause which agrees with מישהו), however if עליו pronoun goes to the very front of the relative clause it will refer to the head noun מישהו, so מישהו (ש)עליו הוא הגן is referring to "someone whom he protected".